1. Field of the Invention
This invention relates generally to display devices and, more particularly, to displays which move visual elements, such as advertising signs or product displays.
2. Description of the Prior Art
U.S. Pat. No. 5,063,377 (Smith) describes a device for producing complex and interesting movements of visual elements around a central axis, but at an increased cost. Varying advertising needs demand an eye-catching display which is also inexpensive and easy to build. The present invention meets the need for an inexpensive and interesting display device, is capable of a multitude of uses and provides and endless variety of movements limited only by the imagination of the builder. Rather than utilize complex electronic circuitry and programming, the present invention utilizes a unique mechanical approach, maintaining simplicity and cost effectiveness.
Therefore, it is an object of this invention to provide a display device, which allows a visual element to be moved in a desired pattern of movement, which is not necessarily the constant rotation of the visual element about a central axis.
It is another object of this invention to provide a display device, which includes multiple visual elements with multiple faces, the visual elements being movable about a support in a desired pattern so as to expose the faces in different directions.
It is another object of this invention to provide a display device, which allows the display of independently movable visual elements on multiple levels of a support structure.
It is still a further object of this invention to provide a display device and method which accomplishes all of the above objectives in varying combinations and at low cost.
Accordingly, a low cost display device is provided whereby visual elements can be independently transported and displayed. In general, the invention comprises a central shaft; at least one support arm, rotatably attached to the central shaft; and a cam member having at least one cam surface, the cam surface positioned so as to be engageable with at least one support arm, the cam member being movable at least axially in relation to central shaft. As the cam member moves axially of the central shaft, a cam surface contacts at least one support arm and moves it circumferentially around the central shaft. The shapes of the cam surfaces provide choreographed movement of the support arms. Visual elements may be attached to the support arms.
Preferably, the cam member is a tubular member having cam slots, through which the support arms extend. The shapes of the slots choreograph the movement of the support arms, and thus the movement of the visual elements attached to the support arms. The cam member is threadably attached to a threaded portion of the central shaft, which may be rotated by a reversible motor or other means. As the central shaft rotates in one direction, the cam member travels axially along the shaft, imparting movement to the support arms. Reversing the rotation of the shaft imparts a reverse movement of the support arms as the cam member travels along the shaft in the opposite direction.
As will be understood, the variety of movement patterns and visual elements is limited only by the imagination of the designer of a particular display device made in accordance with the invention. The number of cam members, the number, spacing and pattern of the cam slots, and the various visual elements which may be moved by the cam interface member is limitless. Thus, the invention herein provides an inexpensive and flexible device for use in a multitude of applications.